Seminar Leo Van Nierop

Leo Van Nierop
McMaster University
Brane back reaction beyond Randall-Sundrum

Phenomenological string models often rely on the probe brane approximation, in which various branes are living in a background geometry, usually with some fluxes turned on. However, they do not act as sources for the geometry and fluxes themselves. Although this approach can be successful, the example of Randall-Sundrum models shows that in some cases the back reaction dominates. I will show an approach to treat the back reaction of codimension 2 branes (with an obvious generalization to higher codimension), and give some examples of applications. Among those is the intriguing possibility to have the on-brane curvature be independent of the brane tensions in compactifications of gauged chiral supergravity on a (topological) sphere, which gives a new approach to the cosmological constant problem.

Thursday, December 15, 2011 - 12:00 - 13:00